Organic-inorganic composite molded product and optical element

Abstract

An organic-inorganic composite molded product formed by molding a composite material of an organic resin and inorganic fine particles is provided, and in this molded product, the average primary particle diameter of the inorganic fine particles is 1 to 30 nm, the concentration of the inorganic fine particles is 25 to 50 percent by volume, and the porosity is 20 to 55 percent by volume. Accordingly, an organic-inorganic composite molded product having a small content of the inorganic fine particles and a significantly low average coefficient of linear expansion of 20*10 −6 to −110*10 −6 /degree Celsius can be manufactured.

1 . An organic-inorganic composite molded product comprising:
 inorganic fine particles having an average primary particle diameter of 1 to 30 nm; and   an organic resin,   wherein the concentration of the inorganic fine particles is 25 to 50 percent by volume, and   the porosity of the organic-inorganic composite molded product is 20 to 55 percent by volume.   
     
     
         2 . The organic-inorganic composite molded product according to  claim 1 ,
 wherein the average coefficient of linear expansion of the organic-inorganic composite molded product is 20*10 −6  to −110*10 −6 /degree Celsius.   
     
     
         3 . The organic-inorganic composite molded product according to  claim 1 ,
 wherein the inorganic fine particles include SiO 2  or ZrO 2 .   
     
     
         4 . The organic-inorganic composite molded product according to  claim 1 ,
 wherein the organic resin is a thermoplastic resin selected from a poly(methyl methacrylate) resin, a polycarbonate resin, a polystyrene resin, and a cyclic olefin resin.   
     
     
         5 . An optical element comprising:
 the organic-inorganic composite molded product according to  claim 1 .   
     
     
         6 . The optical element according to  claim 5 ,
 wherein the optical element comprises a lens which transmits light.   
     
     
         7 . The optical element according to  claim 5 ,
 wherein the optical element comprises a reflective mirror which reflects light.